i wouldnt say they're mean so much as i would that they're just scared and super defensive. put yourself in their position...your fresh out of an egg and your greeted by giants who wanna touch you and look at you and all that. for all you know they could wanna eat you too.
honestly i'd be strikin' and bitin' like mad too.
just takes some time and patience to get them to understand you wont hurt them.